Answer to Question #143206 in Cell Biology for Jake

Question

Discuss the role of receptors in cell signalling

Answer 1

Cells in a multicellular organism are able to communicate to coordinate their activities. Signal transduction pathways regulate multiple cell activities including division, differentiation, migration and degranulation. Such processes enable responses to be made to external factors. The pathway begins at cell surface receptors and ends in the nucleus with proteins that regulate gene expression. Only certain lipid-soluble molecules can cross the cell membrane; others transfer their signal by binding cell surface receptors. The signal transduction pathway are formed by interacting proteins, which can amplify, dampen, or process signals before passing them downstream.

Cell surface receptors are specific proteins that selectively bind a signaling molecule and convert this binding into intracellular signals, altering cell behaviour.

Intracellular receptors are largely ligand-activated transcription factors which, when activated, migrate to the nucleus and bind to DNA, stimulating or suppressing gene transcription.

The second-messenger system is a set of intracellular molecules activated by cell surface receptors and affecting cell function, producing a physiological response. Second messenger systems produce a signal cascade that amplifies the initial signal and facilitates various cellular responses, which vary between cell types.